Abstract: A power steering system includes a pair of wheel steering mechanisms configured to turn a pair of steered wheels of a vehicle, and a coupling mechanism coupling the steered wheels and coupling the wheel steering mechanisms including operating-side and nonoperating-side mechanisms. The operating-side mechanism includes a drive shaft coupled to one end of the coupling mechanism and extending in an axial direction, and a steering operation member engaged with the drive shaft. The nonoperating-side mechanism includes a drive shaft coupled to the other end of the coupling mechanism and extending in an axial direction, and an electric assist device engaged with the drive shaft. The operating-side mechanism includes at least two operating-side stoppers respectively configured to limit right and left turns of the steered wheels. The nonoperating-side mechanism includes at least one nonoperating-side stopper configured to limit any one of right and left turns of the steered wheels.